1. Field of the Invention
This disclosure relates generally to a method for treating organic waste material with a methyl isothiocyanate (MITC)-generating compound. More specifically, the present disclosure is a method for reducing the attraction of pest vectors to organic waste material. Organic waste material from sewage, agricultural processes and other sources is a valuable source of fertilizer. Although useful, organic waste material attracts pests that present a hazard to human health. Such pests include flies, rodents and other organisms attracted to the waste as a potential food source or reproductive environment. Once pests come into contact with waste material they may transport pathogens to humans. Thus, pests are considered vectors for the transport of pathogens.
2. Background
Waste material must attain a specified level of Vector Attraction Reduction (VAR) before it can be applied to land for certain purposes, as required by the United States Environmental Protection Agency (EPA) under 40 CFR 503. Various methods are available to treat organic waste to achieve VAR at levels that meet government standards. General descriptions of acceptable methods of VAR can be found in EPA's Environmental Regulations and Technology manual under the heading “Control of Pathogens and Vector Attraction in Sewage Sludge.”
Current methods for VAR include alkaline treatment, drying, or covering the waste with soil. Each of these treatments comes with disadvantages. Alkaline treatment generally leaves waste material unsuitable for fertilizer use without further costly treatment. An example of alkaline treatment for VAR can be found in U.S. Pat. No. 5,429,750, which discloses a method for reducing vector attraction by raising the pH of the treated material above 12. Drying waste material to achieve VAR is labor intensive and costly. Burying waste material is labor intensive and requires special equipment that may not be readily available. Therefore, a clear need exists for an economically viable method of treating organic waste that achieves the requisite levels of VAR. MITC-generating compounds have been used as a method to kill pathogens in soil, see U.S. patent application Ser. No. 10/548,075 and U.S. patent application Ser. No. 11/581,715, however MITC-generating compounds are not known to have been used as a method of VAR until the present invention.